Nurses, physicians and others involved in the care of patients may need to assess the condition of a patient's tissue for abnormalities. One abnormality of interest is a pressure ulcer. One definition of a pressure ulcer is the International NPUAP-EPUAP Pressure Ulcer Definition which advises “A pressure ulcer is localized injury to the skin and/or underlying tissue usually over a bony prominence, as a result of pressure, or pressure in combination with shear.” Pressure ulcers can develop and worsen quickly and can be life threatening. Another abnormality of interest is a deep tissue injury. The National Pressure Ulcer Advisory Panel (NPAUP) defines a deep tissue injury as “A pressure-related injury to subcutaneous tissues under intact skin. Initially, these lesions have the appearance of a deep bruise. These lesions may herald the subsequent development of a Stage III-IV pressure ulcer even with optimal treatment.” (NPAUP, 2005). It is therefore desirable to be able to identify deep tissue injuries, pressure ulcers, and tissue conditions which are precursors to pressure ulcers or to at least be able to identify the early stages of these conditions (including at times when the condition may not be readily discernible) so that corrective intervention can be taken before the condition becomes life threatening or difficult to heal.